"Kim went to rehab finally because she got arrested, she humiliated her kids and she wants to avoid jail," the source says. "If the arrest hadn't happened, she wouldn't be going to rehab; it would be business as usual. She's in denial that she has a problem."

Richards was arrested on April 16 at the Beverly Hills hotel and charged with public intoxication, trespassing, resisting an officer and battery on a police officer.